LXR linux/arch/arm/mach-alpine/alpine_cpu

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Low-level power-management support for Alpine platform.
   4 *
   5 * Copyright (C) 2015 Annapurna Labs Ltd.
   6 */
   7
   8#include <linux/io.h>
   9#include <linux/of.h>
  10#include <linux/of_address.h>
  11#include <linux/regmap.h>
  12#include <linux/mfd/syscon.h>
  13
  14#include "alpine_cpu_pm.h"
  15#include "alpine_cpu_resume.h"
  16
  17/* NB registers */
  18#define AL_SYSFAB_POWER_CONTROL(cpu)    (0x2000 + (cpu)*0x100 + 0x20)
  19
  20static struct regmap *al_sysfabric;
  21static struct al_cpu_resume_regs __iomem *al_cpu_resume_regs;
  22static int wakeup_supported;
  23
  24int alpine_cpu_wakeup(unsigned int phys_cpu, uint32_t phys_resume_addr)
  25{
  26        if (!wakeup_supported)
  27                return -ENOSYS;
  28
  29        /*
  30         * Set CPU resume address -
  31         * secure firmware running on boot will jump to this address
  32         * after setting proper CPU mode, and initialiing e.g. secure
  33         * regs (the same mode all CPUs are booted to - usually HYP)
  34         */
  35        writel(phys_resume_addr,
  36               &al_cpu_resume_regs->per_cpu[phys_cpu].resume_addr);
  37
  38        /* Power-up the CPU */
  39        regmap_write(al_sysfabric, AL_SYSFAB_POWER_CONTROL(phys_cpu), 0);
  40
  41        return 0;
  42}
  43
  44void __init alpine_cpu_pm_init(void)
  45{
  46        struct device_node *np;
  47        uint32_t watermark;
  48
  49        al_sysfabric = syscon_regmap_lookup_by_compatible("al,alpine-sysfabric-service");
  50
  51        np = of_find_compatible_node(NULL, NULL, "al,alpine-cpu-resume");
  52        al_cpu_resume_regs = of_iomap(np, 0);
  53
  54        wakeup_supported = !IS_ERR(al_sysfabric) && al_cpu_resume_regs;
  55
  56        if (wakeup_supported) {
  57                watermark = readl(&al_cpu_resume_regs->watermark);
  58                wakeup_supported = (watermark & AL_CPU_RESUME_MAGIC_NUM_MASK)
  59                                    == AL_CPU_RESUME_MAGIC_NUM;
  60        }
  61}
  62